In any beverage making process that relies on extraction of flavor ingredients (i.e. coffee beans, tea leaves, malt, hops, etc.), the types and concentrations of ionic species present in water used for extraction impact the flavor and taste of the water, and the beverage product produced from the water. A specific example is coffee or espresso brewing where calcium and magnesium ions are used for extracting desirable compounds from the coffee bean. However, the overall flavor of the water and coffee becomes “chalky,” if the calcium and magnesium ions are present in too high of a concentration.
Similarly, alkalinity is defined as the capacity of an aqueous solution to neutralize an acid. Many of the extracted ingredients in beverages such as coffee and beer brewing are organic acids, and therefore will react with alkaline species in the water, which may negatively alter the flavor profile. In order to maintain a uniform flavor in these beverage making processes, it is useful to control the alkalinity of the ingredient water.